FXUS66 KSGX 061034 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 234 AM PST Mon Feb 6 2023 .SYNOPSIS... A trough will sweep through Southern California this morning, with showers ending by around sunrise. Areas of northeast winds will follow today into Tuesday, strongest in foothills and portions of adjacent inland valleys. High pressure aloft will bring fair and warmer weather with weak offshore flow for the rest of the week. Over the weekend, a trough appears poised to bring some onshore winds and a chance of showers to the region. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Some locally heavy showers tracked through the northeast Inland Empire overnight, with lighter showers in inland San Diego County and the high desert. The showers will end by sunrise. Now that the trough axis of our current system has moved through our region, we'll begin a period of offshore flow that should last for most of the week. In the near term, the offshore flow will produce two surges of northeast winds for pockets of our region, one for late this morning and the second for tonight into Tuesday morning. These will be strongest through and below the Cajon Pass area and in the northern Santa Ana Mountains and northeast Orange County. In general, gusts will be 30 to 40 mph in these somewhat confined pockets with top gusts up to 50 mph at a few isolated foothills. Skies will clear out efficiently today with a dry air mass replacement. With high pressure aloft building, we'll get a warming trend, to which a weaker offshore flow will contribute. Temperatures will climb into the low 70s for some places Tuesday, and continue rising each day through Thursday, the warmest day this week. Temps that day should achieve 80+ for the coastal- inland belt. Skies will be mostly clear, but with some high clouds to accent the blue on Wednesday. The high pressure breaks down Friday and Saturday, allowing for the next trough to bear down on the region this weekend. Chances of showers ramp up on Saturday and, for now, appear to ramp down late Sunday. This is another trough with an interior path, but probably just enough to squeeze out some showers most likely in the mountains and in San Diego County with its northwest flow path. Onshore westerly winds should pick up as well, strongest in the mountains and deserts. Extended guidance including ensembles are widely dispersive, meaning there is a fairly wide range of possibilities regarding the timing and chances of precip, but no solution calls for heavy precip. The overall pattern doesn't change much, with the storm door halfway open for these systems from the northwest. That will keep us in a cool pattern for sure, with alternating onshore and offshore flow. We should get light showers during the occasional trough passages, but this pattern doesn't set us up for heavy precipitation unless or until the jet stream changes and or taps into subtropical moisture. && .AVIATION... 061000Z...SCT-BKN cloud layers with bases 2000-5000 ft MSL and tops to 6000 ft MSL gradually clearing from north to south through 16Z. ISO -SHRA continuing through 14Z as well. Mountain terrain will be locally obscured through about 15Z Mon. After 16Z, a few high clouds and unrestricted vis. West winds with surface gusts 20-30 kt and MOD UDDFS from the mountain crests north and east into the deserts will continue through 12Z, then turn northerly and strengthen slightly through 18Z. Winds weaken during the afternoon, then strengthen again this evening into early Tuesday morning on south/southwest slopes and through/below Cajon Pass. Local gusts 30-40 kt possible in and below the wind prone passes, canyons, and coastal slopes. && .MARINE... Strong west to northwest winds with gusts 25-30 kt, locally up to 33 kt near San Clemente Island, and combined seas of 7-11 feet with steep waves will produce hazardous boating conditions. A Small Craft Advisory remains in effect through Noon. Winds and seas lower this afternoon. No hazardous boating conditions expected Tuesday through Friday. && .BEACHES... A west-northwest swell of 8-9 ft with a period of 7-9 seconds from 290-300 degrees will likely produce surf of 3 to 6 feet with local sets to 7 feet today. Largest waves will occur on exposed west to northwest-facing beaches in central and southern San Diego County, where isolated sets to 8 feet may occur. Gusty onshore winds coincident with this swell will produce rough surf. Swell will lower to 5-7 ft late Monday through Tuesday, but with the period increasing to 12-13 seconds, elevated to locally high surf will likely continue into Tuesday morning, mainly in San Diego County. The surf and strong rip currents will create dangerous swimming conditions Monday and Tuesday. Swell and surf will lower late Tuesday and Wednesday. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...Beach Hazards Statement through Tuesday evening for San Diego County Coastal Areas. PZ...Small Craft Advisory until noon PST today for Coastal Waters from San Mateo Point to the Mexican Border and out to 30 nm- Waters from San Mateo Point to the Mexican Border Extending 30 to 60 nm out including San Clemente Island. && $$ PUBLIC...MM AVIATION/MARINE/BEACHES...SS